فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri - Paris Observatory

The apparent motion of a star across the sky (not including a star's
parallax), arising from the star's velocity through space with
respect to the Sun. Proper motion
is usually tabulated in star catalogs as changes in right ascension and
declination per year or century. See also:
→ proper motion distance.

The distance derived from the → proper motion of an object.
If an object has a known → transverse velocityu, and has an observed angular motion
of dθ/dt, then the proper motion distance is defined as:
d = u/(dθ/dt).